Operational Soil Moisture Prediction Model.
Abstract
The one dimensional problem of the diurnal variations of moisture and temperature at different depths of the thermally active, non-frozen, non-swelling soil layer is considered. It is assumed that we know: (1) Values of all meteorological elements at anemometer level at any time, (2) Moisture and temperature distribution with depths at some initial moment; and (3) Physical parameters and characteristics of the soil and vegetation cover which we shall call canopy for brevity. The model consists of: (1) Partial differential equations of the subsurface hydrology for a non-saturated vapor-liquid flow in the soil, allowing for the moisture removal by the roots of plants. (2) Algebraic empirical and ordinary differential equations for the description of the radiative and turbulent heat transfer between the atmosphere and the soil through the canopy allowing for the influence of condensation or evaporation at the foliage and also the retention of a part of the precipitation by its the foliage. (3) Moisture and vapor balance equations at the surface of the soil. (4) Continuity conditions for heat and vapor fluxes at the top of the canopy. (5) Semiempirical algebraic equations of the type of surface layer equations for a thin atmospheric layer between the canopy and anemometer level. Results of computations are in agreement with experimental data. A few examples of soil moisture computations are presented together with experimental data.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 20, 1985
- Accession Number
- ADA165313
Entities
People
- Lev N. Gutman